Current Research

Exposure to Per-and Polyfluoroalkyl Substances (PFAS) on Cognitive Function in Firefighters in Central Texas

Per- and polyfluoroalkyl substances (PFAS) are a class of artificial chemicals that are fluorinated at the entire or on a portion of the carbon atom chain with a terminal functional group. Due to their unique physicochemical properties (e.g., non-stick, heat and acid resistant, waterproof, oil repellent, and stain resistant), PFAS have been widely used in consumer products and industry (e.g., surface coating and protectant formulations) since the 1940s [1]. Due to their recalcitrant (non-biodegradable) and persistent (i.e., long half-lives) properties, PFAS are now called the “forever chemicals” and have potential for accumulation in the environment and the human body [1,2].

Epidemiological studies have documented the adverse effect of PFAS on human health including cancer, immune suppression, thyroid dysfunction, metabolic effects, increased lipid levels, ulcerative colitis, liver and kidney function in adults [2-4] and neurodevelopment in children, including executive function deficits [5], cognitive dysfunction [6], and attention deficit and hyperactivity disorder [7]. Additionally, evidence from animal studies has suggested that PFAS can reduce function of the nervous system and are potentially neurotoxic and correlate with neurobehavioral dysfunction, such as late-onset Alzheimer’s disease (AD) and learning and memory deficits [1,8-10].

However, the impact of exposure to PFAS on cognitive function among firefighters is unclear. PFAS exposure may be of particular relevance to firefighting because these compounds are used in turnout gear, training activities in airports and military bases, and are a major ingredient of some firefighting foams, such as aqueous film-forming foams (AFFFs) [11-13]. Firefighters may be exposed to PFAS through inhalation of aerosolized foam, direct or indirect skin contact with contaminated personal protective equipment (PPE), as well as hand to mouth transfer during the use of AFFFs [2,14–19]. Exposure to PFAS have been found to be associated with adverse physical health outcomes, such as cancer, kidney disease, and thyroid dysfunction in firefighters [2]. Additionally, firefighters might be under notable stress in their work due to the great workload and psychological stressors dur­ing fire and rescue operations. Unlike many other profes­sions, firefighters are engaged in an occupation in which they are exposed to several stressors (e.g., night shift schedules, sleep deprivation, sudden alarm calls, strenu­ous physical work, exposure to smoke, heat, and other harmful substances during fire suppression) for an unforeseeable amount of time [20]. All the above factors can contribute to short-term and long-term impairment of mental health in firefighters [21].

A number of former and active military bases are located in Central Texas (including Austin, Buda, Kyle, San Marcos, and New Braunfels) so the firefighter training and fire and rescue services are frequent in this area. Firefighters may have a higher exposure to PFAS from fire suppression activities and during the salvage and overhaul phase of a fire event compared to their non-firefighter counterparts. However, the effects of PFAS on health outcomes among residents in Central Texas have not been studied and there is no research examining cognitive function in firefighters, especially those who are currently on “active duty” (i.e., assigned to a fire station).

Dr. Pan and her research team aims to identify and quantify PFAS in tap water and PPE wash water after firefighting emergency or other rescue services and assess the cognitive function in firefighters in relation to PFAS concentrations in water and blood. Findings of the research will elucidate the source of PFAS exposure for firefighters, thus highlighting opportunities for environmental scientists to develop effective intervention and prevention strategies to reduce their workplace exposure, and provide evidence to enhance our understanding of the health implications, in particular cognitive function, of PFAS exposure and fill the data gaps to interpret the mechanisms responsible for brain health.

The project is currently recruiting firefighter and non-firefighter participants! Registration for Participation 

References

  1. Foguth RM, Flynn RW, de Perre C, et al. Developmental exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) selectively decreases brain dopamine levels in Northern leopard frogs. Toxicol Appl Pharmacol. 2019;377:114623. doi:10.1016/j.taap.2019.114623
  2. Trowbridge J, Gerona RR, Lin T, et al. Exposure to Perfluoroalkyl Substances in a Cohort of Women Firefighters and Office Workers in San Francisco. Environ Sci Technol. 2020;54(6):3363-3374. doi:10.1021/acs.est.9b05490
  3. Weng X, Liang H, Tan Y, et al. Mixed effects of perfluoroalkyl and polyfluoroalkyl substances exposure on cognitive function among people over 60 years old from NHANES. Environ Sci Pollut Res Int. 2022;29(21):32093-32104. doi:10.1007/s11356-021-17789-5
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  5. Vuong, A.M., Yolton, K., Webster, G.M., Sjodin, A., Calafat, A.M., Braun, J.M., Dietrich, K.N., Lanphear, B.P., Chen, A., 2016. Prenatal polybrominated diphenyl ether and perfluoroalkyl substance exposures and executive function in school-age children. Environ. Res. 147, 556–564.
  6. Skogheim, T.S., Villanger, G.D., Weyde, K.V.F., Engel, S.M., Suren, P., Oie, M.G., Skogan, A.H., Biele, G., Zeiner, P., Overgaard, K.R., Haug, L.S., Sabaredzovic, A., Aase, H., 2020. Prenatal exposure to perfluoroalkyl substances and associations with symptoms of attention-deficit/hyperactivity disorder and cognitive functions in preschool children. Int. J. Hyg. Environ. Health 223, 80–92.
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  10. Pierozan P, Karlsson O. Differential susceptibility of rat primary neurons and neural stem cells to PFOS and PFOA toxicity. Toxicol Lett. 2021;349:61-68. doi:10.1016/j.toxlet.2021.06.004
  11. Laitinen, J. A.; Koponen, J.; Koikkalainen, J.; Kiviranta, H. Firefighters’ Exposure to Perfluoroalkyl Acids and 2-Butoxyethanol Present in Firefighting Foams. Toxicol. Lett. 2014; 231: 227−232.
  12. Jin, C.; Sun, Y.; Islam, A.; Qian, Y.; Ducatman, A. Perfluoroalkyl Acids Including Perfluorooctane Sulfonate and Perfluorohexane Sulfonate in Firefighters. J. Occup. Environ. Med. 2011;53:324−328.
  13. Moody, C. A.; Field, J. A. Perfluorinated Surfactants and the Environmental Implications of Their Use in Fire-Fighting Foams. Environ. Sci. Technol. 2000;34:3864−3870.
  14. Gainey, S. J.; Horn, G. P.; Towers, A. E.; Oelschlager, M. L.; Tir, V. L.; Drnevich, J.; Fent, K. W.; Kerber, S.; Smith, D. L.; Freund, G. G. Exposure to a Firefighting Overhaul Environment without Respiratory Protection Increases Immune Dysregulation and Lung Disease Risk. PloS One 2018;13: No. e0201830.
  15. Navarro, K. M.; Cisneros, R.; Noth, E. M.; Balmes, J. R.; Hammond, S. K. Occupational Exposure to Polycyclic Aromatic Hydrocarbon of Wildland Firefighters at Prescribed and Wildland Fires. Environ. Sci. Technol. 2017, 51, 6461−6469.
  16. Nilsson S, Smurthwaite K, Aylward LL, et al. Serum concentration trends and apparent half-lives of per- and polyfluoroalkyl substances (PFAS) in Australian firefighters. Int J Hyg Environ Health. 2022;246:114040. doi:10.1016/j.ijheh.2022.114040
  17. Peaslee, G.F., Wilkinson, J.T., McGuinness, S.R., Tighe, M., Caterisano, N., Lee, S., Gonzales, A., Roddy, M., Mills, S., Mitchell, K. Another pathway for firefighter exposure to per- and polyfluoroalkyl substances: firefighter textiles. Environ. Sci. Technol. Lett. 2020;7: 594–599. https://doi.org/10.1021/acs.estlett.0c00410.
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  19. Shaw, S.D., Berger, M.L., Harris, J.H., Yun, S.H., Wu, Q., Liao, C., Blum, A., Stefani, A., Kannan, K. Persistent organic pollutants including polychlorinated and polybrominated dibenzo-p-dioxins and dibenzofurans in firefighters from Northern California. Chemosphere.2013; 91:1386–1394. https://doi.org/10.1016/j.chemosphere.2012.12.070.
  20. Hemmatjo R, et al. The Effects of Live-Fire Drills on Visual and Auditory Cognitive Performance among Firefighters. Annals of Global Health. 2020; 86(1): 144, 1–8. DOI: https://doi.org/10.5334/aogh.2626
  21. Orysiak, J., Młynarczyk, M., Piec, R. et al. Lifestyle and environmental factors may induce airway and systemic inflammation in firefighters. Environ Sci Pollut Res.2022; 29:73741–73768 https://doi.org/10.1007/s11356-022-22479-x
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